1,721,018 research outputs found
Mesure et comparaison du déploiement de l’attention visuelle : application à l’évaluation de la qualité d’expérience dans un contexte de contenus hyper-réalistiques
No full textLes nouveaux contenus hyperréalistiques nécessitent le développement de nouveaux protocoles et modèles pour quantifier l’expérience utilisateur. L’étude du déploiement de l’attention visuelle est considérée comme un moyen intéressant pour comprendre et améliorer la qualité d’expérience (QoE). Dans ce contexte, des méthodes basées saillance, ne considérant que l’information spatiale, ont principalement été utilisées. Dans cette thèse, nous nous proposons donc d’étudier le déploiement de l’attention visuelle, en considérant la dimension dynamique des comportements oculaires, et ses applications possibles en QoE. Dans un premier temps, nous présentons un nouveau cadre méthodologique basé sur des modèles de Markov cachés permettant la classification et la mesure de similarité des chemins oculaires pour différentes dimensions de la QoE (mémorabilité, fidélité visuelle). Au-delà de la comparaison des comportements attentionnels, cette thèse s’intéresse également à la mesure expérimentale du déploiement de l’attention visuelle, en particulier dans un contexte d’études en crowdsourcing sans oculomètre. Nous avons ainsi adapté et testé la métaphore "Bubble- View" pour l’évaluation de l’influence des opérateurs de mappage de tons sur le déploiement de l’attention visuelle. Finalement, les outils présentés dans cette thèse pour la mesure, la modélisation et la comparison du déploiement de l’attention visuelle ont été appliqués à la prédiction de la préférence d’images mappées à partir d’une métrique basée sur un algorithme d’apprentissage automatique.The emerging hyper-realistic contents require the development of new experimental protocols and models for quantifying and predicting the user experience. Visual attention deployment is considered as a good proxy to understand and enhance the quality of experience (QoE). In this context, mostly saliencybased methods have been used considering only spatial information. Therefore, this thesis proposes to study visual attention deployment considering the dynamic dimension of gaze behaviors and its application for QoE. First, we develop a new framework based on Hidden Markov model for the classification and the similarity evaluation of scanpaths and assess it for different QoE dimensions (memorability, visual fidelity). Beyond the comparison of visual behaviors, we also address the measurements of visual attention deployment in in-lab and crowdsourcing experiments, testing the possibility to avoid eye-tracking devices. We adapt and test the "BubbleView" metaphor to assess the impact of tone-mapping operators on visual attention deployment. Finally, based on the different tools for measuring, modeling, and comparing visual attention deployment, we develop a new machine learning metric to predict the preference between tone-mapped images
Perception of Luminous Atmospheres in Iconic Buildings : Analysis of Impressions in Real Situation and through Omnidirectional Photographs in an Immersive Head-Mounted Display (HMD)
No full textCette thèse s’inscrit au croisement des domaines des ambiances lumineuses, de la pédagogie architecturale, de la perception et de l’immersion. Elle se concentre principalement sur la conception et la mise en oeuvre d’une nouvelle méthodologie expérimentale ayant pour but d’évaluer la capacité des photographies statiques omnidirectionnelles stéréoscopiques HDR, projetées dans un casque immersif, à restituer fidèlement des impressions subjectives d’ambiances lumineuses vécues dans des architectures de référence. Une attention particulière est accordée à l’influence des opérateurs de mappage de tons (TMOs). La méthodologie développée comprend plusieurs étapes : la constitution d’une grille d’analyse des ambiances lumineuses de lieux remarquables basée sur des propos d'experts ; la mise en place d’une méthode de collecte de données in situ pour l’évaluation des ambiances lumineuses (questionnaire, relevés lumineux, captationsphotographiques omnidirectionnelles HDR) ; et la mise en place d’une méthode d’évaluation des ambiances lumineuses dans un casque immersif. Les résultats fournissent des connaissances sur les caractéristiques des ambiances lumineuses in situ de sept architectures remarquables et sur la fidélité de perception de chaque impression d’ambiance lumineusedans le casque immersif en fonction des TMOs. Ils mettent également en évidence le lien entre les impressions sélectionnées par les propos d’experts et celles évaluées in situ et dans le casque immersif. Ces connaissances sont utiles pour des applications pédagogiques futures en architecture.This thesis is at the crossroads of the fields of luminous atmospheres, architectural pedagogy, perception and immersion. It focuses on the design and implementation of a new experimental methodology for evaluating the ability of HDR stereoscopic omnidirectional static photographs, projected in an immersive Head-Mounted Display (HMD), to faithfully reproducesubjective impressions of luminous atmospheres experienced in reference architectural places. Specific consideration is given to the impact of tone mapping operators (TMOs). Our methodology involves several steps: designing a grid for analyzing the luminous atmospheres of iconic places based on expert judgement; implementing in situ data collection to assess luminous atmospheres (questionnaire, light measurements, HDR omnidirectional photographic recordings), and implementinga method for assessing luminous atmospheres in an HMD. The results provide knowledge about the characteristics of the in situ luminous atmospheres of seven iconic buildings and the perceptual fidelity of each luminous atmosphere’s impression in the HMD, depending on the TMOs. The findings also highlight the relationship between the impressions selected by the experts and those assessed in situ and in the HMD. This knowledge is useful for future pedagogical applications in architecture
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Impact of visual immersion on perception of urban morphology and density in 3D city models
No full textInternational audienceUrban information visualization is an essential tool for decision process in urban planning. Nowadays, more and more urban visualizations incorporate virtual 3D city scenes to better convey spatial and morphological information. On the other hand, the development of consumer grade VR devices as Head Mounted Displays (HMD) enable to visualize urban information with a greater degree of immersion. These new ways to render and display 3D city models may have a significant impact on the perception of urban morphology and, consequently, on the interpretation of the urban visualization. In this paper, we present a subjective experiment to evaluate the impact of visual immersion - field of view, stereoscopy and allocentric or egocentric representations - on the perception of urban morphology and density in 3D city models. Obtained results can be useful to improve urban visualization, but also to better understand perception, user behavior and navigation in 3D virtual environments
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